Our past studies lead us to believe that nerves in the pulps of teeth may play a regulatory role in dentin formation. Resection of nerves innervating the teeth followed by stimulation of the dentin causes abnormal amounts of irregular dentin to develop in the pulps. Current studies propose determining the relationship of the nerves in teeth to the rate and quality of dentin formation. Ultrastructural studies of 5-hydroxydopamine (5-OH-DA) injected mice has aided us in the identification of adrenergic endings and their relationship to the dentin forming cells. Current ultrastructural studies involving resection of the inferior alveolar and/or cervical sympathetic nerves and stimulation of the dentin coupled with 5-OH-DA staining is clarifying the role of nerves in the process of dentinogenesis. Further studies will be carried out on the rate of synthesis and release of precursor collagen by odontoblasts using L proline-2,3-H after stimulation and/or resection to further our knowledge of the effects on the rate of dentin formation.